KARAK, Iraq -- At the end of the bridge in this village that straddles Kurdish-controlled Iraq and Saddam Hussein's Iraq, a 30-foot flame billowing with black smoke scars the blue sky.

Every day, an Iraqi border guard nicknamed Abdullah "The Beast" stops Kurdish residents as they cross from the autonomous Kurdish region. He siphons gasoline from their cars, dumps it on the roadside, and lights it. Then he tosses into the flames the goods he has confiscated from Kurdish travelers -- vegetables, household items, books.

According to the Kurds who cross the bridge and provided this account, "The Beast" has come to embody the hatred and humiliation that the Iraqi regime has heaped upon them daily for generations.

The notorious guard "will soon get what is coming to him," said Rabar Tariq, a 28-year-old taxi driver who paused at the Kurdish side of the bridge before driving back to his village. "Some day, he will hang from this bridge."

Such thoughts of retribution are just one example of the pent-up Kurdish anger toward officials of Hussein's Ba'ath Party at the frontline in northern Iraq. With these emotions festering, opposition leaders in Kurdish-controlled areas worry that a US-led war against Iraq could touch off a cycle of lawlessness and revenge killing in this region, home to 3.5 million Kurds.

The worry is exacerbated by Turkey's failure to pass a resolution allowing some 60,000 US combat troops to use bases in Turkey to open a northern front against Iraq. That massive invasion force was intended not only to overwhelm Baghdad with a two-pronged attack, but also to seal the minority areas of Iraq in an effort to prevent ethnic hatreds from spiraling out of control.

Abdullah's callousness at the border is backed by might. Just 200 yards from the bridge, Iraqi military posts loom over the Kurdish villages. Operators of the tanks and heavy artillery do not dare to cross the UN-imposed no-fly zone, which was established after the 1991 Gulf War to protect the Kurdish minority in the north. Another no-fly zone protects the Shiite minority in the south.

The border guard's cruelty seems petty compared with the chemical attacks Hussein used to devastate the Kurdish villages in the late 1980s, which killed some 30,000 people, according to human rights groups. In the south, an estimated 200,000 Shiites were killed after the United States failed to support their 1991 uprising, the groups say, while untold numbers are said to have been tortured and killed in Iraqi prisons over the years.

All that bitter history will make Iraq a tinderbox in the aftermath of an invasion.

Zalmay Khalilzad, the White House envoy to the Iraqi opposition, which gathered last week at a conference in northern Iraq, said: "Saddam has abused this country. . . . So there is a lot of potential for revenge attacks, for people taking the law into their own hands. We will have to respond to that."

Dr. Saedi Barzinji, a Kurd who serves as a legal adviser to the Iraqi opposition and is president of the Salahaddin University in Arbil, said that US and Iraqi opposition officials will have to pay careful attention to the possibility of lawlessness. At the same time, he said that ethnic clashes were unlikely to erupt because the minority groups -- the Sunni and Shiite Muslims, Christians, ethnic Kurds, and Turkomans -- traditionally have sought unity.

"Among the people, this is a society of tolerance," Barzinji said. "The government that has so brutalized the minorities has done so against the grain of a culture of Iraq. Whether the hatreds that government policy has created will surface after Saddam depends on which kind of government we have in Iraq . . . But I think all Iraqis agree we have suffered enough under Saddam."

There was evidence of that near the village of Harir, about 60 miles northwest of here. In a valley surrounded by snowcapped mountains deep in Kurdish-controlled Iraq, paving crews were repairing a 1.5-mile military airstrip for possible use by US forces. Just across from the airstrip lay the remains of the village of Harwata.

Mohammed Ibrahim El Sheikh, 52, walked among the rubble pointing out the homes of 150 families who once lived in Harwata, before Hussein's forces leveled the village in 1988. The assault was part of what was known to human rights groups as the Anfal campaign to crush the Kurdish peshmerga, militias who resisted Hussein's regime.

The Iraqi Kurds, a non-Arab ethnic group that makes up nearly one-fourth of Iraq's population of 23 million, have long sought autonomy from the government, which in turn has tried repeatedly to crush any move for Kurdish self-rule. Significant Kurdish populations also live in Turkey and Iran.

The human rights group Middle East Watch supports the Kurdish claims that 12 towns and 3,000 villages were destroyed during the 1988 Anfal operation. Tens of thousands of people died, Middle East Watch says, and at least 1.5 million were uprooted from their homes and either deported or forced into the misery of makeshift camps for the displaced.

"The Ba'ath Party officials came and told us to leave or they would use gas," Sheikh said as he walked with the aid of a hand-carved wooden cane through the rubble. It was a very real threat, considering the deadly gassing of villages that year that has been documented throughout the Kurdish areas.

"They gave us two days to pack our things and we all left," he said, adding that the residents fled to other towns to live with family or ended up in camps.

When they cautiously returned a year later, they saw the destruction that Hussein's military had inflicted on their homes with dynamite and bulldozers.

Fifteen years later, only 20 families have returned to Harwata, Sheikh said. They have rebuilt their homes out of the rubble. The UN-donated tarps that serve for roofs flap in the cold wind coming down from the rugged mountains.

"People will never forget what happened to them here," he said. "I don't know whether you can bury all of that pain away. Only God knows what is to come."